Best Propane Tankless Water Heaters – Buying The Right Heating Device

No natural gas? Have you thought about using efficient liquid propane? Are you looking for comfortable and convenient use of hot water when away from home? Don't worry; propane tankless water heaters are the solution you are looking for.

Tankless heaters powered by propane gas or liquid propane (LP or LPG) can be used for domestic water and space heating in the same way as natural gas. If you plan to go camping, stay at the cottage or RV-ing, and if natural gas and/or electricity are not available, you can use propane-powered portable heaters.

Combining propane's effectiveness and the convenience of tankless water heaters, these devices will offer fantastic quality and versatility. Come and learn more about them!

Efficiency and excellent performance that's what LP offers over natural gas, but not the only advantage you will get. Propane sometimes makes more sense; it is a lot cleaner for the environment and even easier to use.

When you combine propane and tankless water heaters – the result is even better. Superb performance, convenience, and outstanding results overall – that's what you get with propane tankless water heaters.

What do propane tankless water heaters offer? Benefits & advantages

Tankless water heaterTankless water heater

Low costs

Propane heaters are not the most affordable fuel but could be cheaper than electricity or oil. And combining it with the tankless water heater, which provides greater savings over tank-type (over 30%), you will get better savings throughout the year.


As it offers more power than a heat pump and as it is more efficient than natural gas, a propane heater could offer up to 95% of heating efficiency – making it a great option in some regions. When you add the tankless feature, you can save even more propane and reduce costs exponentially while having a longer lifespan.


As well as producing less carbon dioxide, a propane tankless water heater also reduces the carbon footprint and does not contaminate the environment as bad as others. Being one of the cleanest fossil fuels in the market (more than gas and oil), it will help you heat water more efficiently and without side effects.


Easily stored, transported, and even reliable due to its liquid state, propane is very convenient to use. Capable of heating practically anything, it is also incredibly fast to heat (almost twice as fast) as other fuels and even lasts more due to its efficiency.


Propane tankless water heaters are safe to use.

Typically, devices that use LP need to be hundreds of times more resistant and reliable than others. Why? Because propane can travel faster, so it becomes a little squishier in devices. And thanks to its safer formula, propane is actually non-harmful when ignited, so you get a safe fuel option in every way.

Propane vs. natural gas


Being stored in larger quantities and providing a superior BTU capacity per cubic quantity, propane is almost twice as useful for heating water. While natural gas offers 1,051 BTU per cubic foot, propane offers up to 2,500, translating to higher efficiency for heating devices.


Natural gas is often a much more cost-effective solution than propane. The price of propane, on the other side, is lower than oil or electricity. The propane heaters are also cheaper to repair than different types.

Environmental impact

Natural gas, when ignited, produces NOx, which is a greenhouse gas that affects the environment. Propane, however, does not do that despite being a similar fuel. Being more efficient and providing more energy per gallon, propane eventually releases much fewer gasses to the atmosphere while producing more energy.

What do tankless heaters offer? Advantages & benefits

Now that you learn some about propane, it is time to know a little more about tankless or on-demand heaters and compare them to tank-type models.

Less waste

Tankless heaters are more effective in using water, as they hold almost no water and dispose of fewer amounts. The tank-less design and quality of construction also allow tankless heaters to produce less environmental damage when disposed of.

Cleaner water

Without tanks that produce contaminants such as rust and scales – tankless heaters will provide faster and cleaner water directly to your shower or sink. As there is no standing water, hot water is always fresh.

More water

Don't need to wait for the heater to warm up the water; simply turn up the device and open the tap, and hot water will immediately come your way (depends on the pipe length and recirculation availability). Even after hours of use, the water is still hot. Tankless can deliver an endless supply of hot water to any fixture in your home, even multiple fixtures simultaneously.

More space

Tank heaters occupy too much space in houses. With a tankless heater, you obtain one of the most convenient and space-oriented devices in the market, as they are wall-mounted and as small as a small suitcase.

More efficiency

Without saving up water and heating it in the meantime, on-demand water heaters use up to 40% less energy than tank heaters. This is translated into less monthly costs and less wasted energy & water.

Longer lifespan

Almost all tankless heaters not only last longer due to their innovative design, but they also demand less maintenance and have more replaceable parts. This means you have a much more convenient and reliable product.

Why use propane tankless water heaters

Now that you know why tankless heaters are so amazing and why propane is so effective, it is time to understand why tankless water heaters may provide the best results you can think of. Here's why to use tankless propane water heaters:

  • Propane tankless heaters are more efficient than electric tankless heaters, even natural gas type. Due to high energy factors, propane models are often found as Energy Star rated models. Homeowners have options to buy mid-efficient or non-condensing, and ultra-efficient or condensing models, which qualify for rebates and grants.
  • Propane tankless heaters produce less carbon emissions.
  • Propane tankless heaters may qualify the user for tax credits depending on the use and location.
  • A propane tankless heater does not waste as much energy as a gas tank heater due to higher efficiency.
  • A propane tankless heater will not store water to waste any energy heating it up.
  • A propane tankless heater is much smaller than a gas tank-type heater.
  • A propane tankless heater can last up to 20 years working, which is up to 10 years more than a tank type.
  • A propane tankless heater demands less maintenance and care than a conventional type.

Popular propane tankless water heaters in North America

Top selling propane tankless heaters reviews!

Takagi T-H3-DV-P – 199,000 BTU

Takagi T-H3-DV-PTakagi T-H3-DV-P

The Takagi T-H3-DV-P is a high-quality tankless heater that works with liquid propane, offering up to 10 GPM of continuous water flow and over 90% efficiency. It is one of the most energy-efficient devices in the market, which makes it Energy Star compliant.

It weighs only 66 lbs. which is a standard for most tankless heaters, yet it comes with up to 199,000 BTU of power, which is a very high heating capacity for its size, plus an excellent water flow and only 55 dB noise level. If you get this heater, you will easily get a fantastic performance at all times.

Benefits of the Takagi T-H3-DV-P:

  • More hot water due to superior water pressure
  • Excellent design for saving space and providing comfortable storing
  • Provides outstanding energy conversation
  • It comes with digital safety features
  • Promotes lower NOx emissions than most
  • Can provide water for up to four bathrooms at the same time

Rinnai RUC98iP Ultra Series – 199,000 BTU

Rinnai RUC98iPRinnai RUC98iP

Being one of the most efficient, compact, and powerful models in the market and with both available to use gas and propane the Rinnai RUC98iP is an excellent choice. It provides a superb 199,000 BTU capacity with a super-efficient performance and low NOx emissions.

It can keep your house ready to use hot water at any time without problems. Having 95% thermal efficiency and modulating power, you are talking about an excellent device entirely. Even when adding how easy it is to install and transport and its high 9.8 GPM water capacity, this model is a top-notch option without a doubt.

Benefits of using the Rinnai RUC98iP:

  • Compact and lightweight design with the flexible venting system makes the installation easy
  • Much more energy-efficient than most with 95% thermal efficiency
  • Provides low NOx emissions compared to most heaters
  • Long-lasting build for up to 12 years of working straight
  • Excellent 199,000 BTU capacity enough for large houses with multi-baths

Eccotemp FVI-12 – 74,500 BTU

Offering 74,500 BTU, the Eccotemp FVi-12 is not an option to overlook if you need the portable unit. With its 3.6 GPM of water consumption, plus an amazing set of digital features such as a temperature display and electronic ignition, it can become a huge change for your cottage.

Using LP just makes this device a perfect addition to any house, as it becomes more efficient, reliable, durable, and hugely convenient. Especially for its compact design and 120v electrical compatibility, this heater is a top-notch choice.

Benefits of using the Eccotemp FVI-12:

  • Works without the tank or with the tank if you need to
  • Provides the most continuous flow of hot water out there
  • Excellent for smaller home, cottage, or cabin for its efficiency and top-notch performance at 74,500 BTU
  • Installs easily on any small space due to its compact design and excellent ventilation
  • Easy to use thanks to a digital display
  • Produces little noise
  • It can be used in practically any place with a 120 v electrical connection

How do propane tankless water heaters work?

Propane tankless water heaters are designed to heat water using one or two heat exchangers. They do not store water.

As the water passes through the heat exchanger, the flame igniter activates while the gas valve opens. The fan starts, and once the right amount of gas and air is established, the gas burner ignites, heating water passing through the heat exchanger. Depending on the outgoing temperature of hot water and demand, the unit adjusts the flame (modulation) to maximize efficiency and performance.

Every modern tankless unit is equipped with an electronic board and a microchip that controls and monitors the operation. There are also sensors, such as the flow sensor, which detects when the tap is open, and there is a call for hot water. Every tankless also includes temperature sensors and safety elements to protect the unit.

Models equipped with the recirculation system deliver hot water faster than those without the pump.

How is propane gas delivered?

Propane gas is delivered to your home in trucks and is stored in propane tanks. Tanks come in various sizes, from 20-lb, typically used for barbeques, to 1000-lb used for homes over 4,500 square feet.

Homes with 2,500 square feet would need a 500-gal tank, which is sufficient to run multiple appliances, including a tankless water heater. You would need a refill every six months with such a size, but it depends on the usage.

Propane tankless water heater vs. tank-type

  • Propane tankless water heaters heat water on demand, while tank-type stores water inside the tank.
  • Propane tankless delivers an unlimited amount of hot water, while tank-type has a limited capacity, ranging from 2 to 100 gallons.
  • Tankless is more advanced than tank-type.
  • Propane tankless heaters are small, compact, and space-saving, usually installed on the wall, while tank-type heaters are large, bulky, and typically sit on the floor.
  • Tankless can be installed indoors and outdoors, while tank-type only indoors.
  • Most tankless models have an efficiency ranging from 80 to over 90%, while tank-type efficiency goes from 60% to over 90%.
  • Most propane tankless models include modulating gas burner, while from tank-type only some.
  • Propane tankless water heaters are designed mostly with power and power direct venting systems, while tank-type also includes an atmospheric and direct vent.
  • Whole-house tankless units require electricity to operate, while some tank-type do not. There are also small and portable tankless models for mobile homes, RVs, cottages, and outdoors that are battery-operated.
  • Most propane tankless heaters are low or ultra-low NOx, while tank-type are not.
  • Almost all propane tankless water heater components can be replaced, while with the tank-type, that is not possible.

Related: Propane tankless vs. electric tank water heaters

How much does it cost to run a propane tankless water heater?

According to Rinnai tankless water heaters' manufacturer, the annual operating costs of high-efficiency propane tankless water heaters (EF is 0.81) is approximately $552, while for natural gas models is $228. Homeowners of the ultra-high efficiency propane models (EF is 0.92) would spend around $487 per year, while for natural gas type, about $201. The above data is from 2017.

Do propane tankless water heaters need to be vented?

Every gas-operated water heater, including propane tankless, has to be vented. Since there are two types, indoor and outdoor, indoor models must remove the products of combustion to the outside atmosphere, often using power or power direct venting system. In contrast, the outdoor models are ventless – they do not utilize a venting system.

Can you convert a propane tankless water heater to use natural gas?

With the approved gas conversion kits, some propane tankless water heaters can be converted from propane gas to natural gas and vice versa. The conversion kits must be used and installed by a qualified installer. Gas conversion is not complicated nor time-consuming.

There are only a few tools needed, such as a screwdriver, manometer, and a gas leak detector. An installer will have to install new gas manifold nozzles and a gasket, setting the DIP switch on the PCB to the correct position, check and adjust the gas supply pressure according to the manufacturer's instructions.


There's no other device as efficient and convenient as tankless propane water heaters are. It is easy to install, much easier to use, and needs less maintenance than other hot water heaters – getting one of these is a splendid idea. However, choosing one is not that easy.

That is why we have provided you with many helpful buying tips and reviewed three models, two of which are used for whole-house heating of potable water and one for portable heating. Our choices of propane tankless water heaters will meet your standards entirely and provide the performance and efficiency you need.